The coils in a toaster convert electrical energy into thermal energy. Heat from the coils is used to toast the bread. How is the heat from the coils transferred to the bread?

By convection and radiation.

The heat from the coils in a toaster is transferred to the bread through a process called conduction. Conduction is the transfer of heat through direct contact between objects that are at different temperatures.

When the toaster is turned on, electrical energy flows through the coils, causing them to become hot. The coils are usually made of a material with high electrical resistance, such as nichrome wire. As the electrical energy is transferred to the coils, it is converted into thermal energy, which makes the coils heat up.

The hot coils then come into contact with the bread slices. As the bread touches the coils, the heat is transferred from the coils to the bread through conduction. The molecules in the coils vibrate rapidly due to the heat, and this vibration is transferred to the molecules in the bread, which causes them to also vibrate and heat up.

Conduction is an efficient way to transfer heat between objects that are in direct contact. In the case of a toaster, the direct contact between the hot coils and the bread allows for the efficient transfer of heat, resulting in the toasting of the bread slices.